import math

times=math.ceil(math.log(0.1/0.0005,2))


def fun(x):
    return x**3-x**2-1

#times=1
def d2(a,b,times):
    if times==0:
        return (a+b)/2
    mid=(a+b)/2
    if fun(mid)>0:
        return d2(a,mid,times-1)
    elif fun(mid)<0:
        return d2(mid,b,times-1)
    else:
        return mid

print(1.4)
print(1.5)
print("%.3f"%d2(1.4,1.5,times+1))